is a catch can needed? why not just a breather filter?
01-23-2003, 04:11 PM
#1
Honda-Tech Member
Thread Starter
is a catch can needed? why not just a breather filter?
i was wondering....why not just install one of those mini k&n breather filters on my valve cover so to prevent the "detonation causing fumes" from entering my intake? seems easier and cheaper than a catch can. maybe i dont fully understand something.
thanks
thanks
01-23-2003, 04:14 PM
#3
Honda-Tech Member
Thread Starter
Re: is a catch can needed? why not just a breather filter? (Ek00si)
i have, and i've seen diagrams that explain how the catch can works. but i didnt find an answer to my original question so i posted.
thanks.
thanks.
01-23-2003, 05:08 PM
#5
Honda-Tech Member
Thread Starter
Re: is a catch can needed? why not just a breather filter? (Farnsrocket)
ok i'll be specific here to make sure i do this right: i'll be supercharging a b16a1 at 6psi. do i need a catch can? do i need a breather filter? i'm still confused, sorry.
thanks
thanks
01-23-2003, 05:13 PM
#6
New User
Join Date: Mar 2001
Location: San Diego, CA, usa
Posts: 572
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (keebler65)
Here an old diagram from Endyne's TOO...
Sounds like a worthwhile investment for your blown setup.
Good luck with the setup!
[Modified by Pritos, 6:14 PM 1/23/2003]
Sounds like a worthwhile investment for your blown setup.
Good luck with the setup!
[Modified by Pritos, 6:14 PM 1/23/2003]
01-23-2003, 05:44 PM
#7
Honda-Tech Member
Join Date: Jan 2002
Location: motor city, mi
Posts: 398
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (Pritos)
Why do you need to run a line from the catch can to the intake manifold? Can you just put a breather on top of catch can. That would produce 0 oil vapor being pulled back into the engine.
Trending Topics
01-23-2003, 05:53 PM
#8
Join Date: Nov 2001
Location: USA
Posts: 1,492
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (salt)
Somebody correct me if I'm wrong, but you run a line from the can to the manifold so the PCV valve will have vacuum to operate correctly.
01-23-2003, 05:57 PM
#9
Honda-Tech Member
Join Date: Sep 2002
Location: USA
Posts: 483
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (Farnsrocket)
But the pcv valve is closed when under boost so it wouldn't even help when your boosting right? So you would need to setup the catch can in a way as to filter the vapors when it is under boost and not under boost, maybe two catch cans, one for when you not boosting as the diagram shows and another one setup some how for when you are boosting. I am confused on this as well earl, tony 1, where you at?
01-23-2003, 06:52 PM
#10
Honda-Tech Member
Join Date: Mar 2002
Location: Anaheim, CA, USA
Posts: 6,093
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (Ek00si)
But the pcv valve is closed when under boost so it wouldn't even help when your boosting right? So you would need to setup the catch can in a way as to filter the vapors when it is under boost and not under boost, maybe two catch cans, one for when you not boosting as the diagram shows and another one setup some how for when you are boosting. I am confused on this as well earl, tony 1, where you at?
01-23-2003, 07:01 PM
#11
Honda-Tech Member
Join Date: Jan 2002
Location: Colorado Springs, CO, USA
Posts: 1,822
Likes: 0
Received 1 Like
on
1 Post
Re: is a catch can needed? why not just a breather filter? (ninesecrx)
So... minus the legal aspect, could you just remove the line from the PCV oil box on the back of the block and dump it into the atmosphere? Then, put a breather on the valve cover outlet (that originally goes to the inake piping)?
Would doing either/both of these eliminate a needed vacuum to draw the vapors out of the valve cover/oil separator box?
Would doing either/both of these eliminate a needed vacuum to draw the vapors out of the valve cover/oil separator box?
01-23-2003, 07:31 PM
#12
Join Date: Nov 2001
Location: USA
Posts: 1,492
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (servion)
Ok, now I was just a little confused until I read this thread that I remembered reading last year, it's really good in regards to boosted cars!
https://honda-tech.com/zerothread?id=248837
So Mike, won't the valve cover breather filter let excess pressure escape when the PCV is shut under boost if you have a PCV valve and catch can hooked back into the mani? I thought your dad (Earl) said that in the post above.
I still think you will need a vacuum source to draw vapors out when you are not boosting. Maybe I am wrong here.
https://honda-tech.com/zerothread?id=248837
So Mike, won't the valve cover breather filter let excess pressure escape when the PCV is shut under boost if you have a PCV valve and catch can hooked back into the mani? I thought your dad (Earl) said that in the post above.
So... minus the legal aspect, could you just remove the line from the PCV oil box on the back of the block and dump it into the atmosphere? Then, put a breather on the valve cover outlet (that originally goes to the inake piping)?
Would doing either/both of these eliminate a needed vacuum to draw the vapors out of the valve cover/oil separator box?
Would doing either/both of these eliminate a needed vacuum to draw the vapors out of the valve cover/oil separator box?
01-23-2003, 07:50 PM
#13
Honda-Tech Member
Thread Starter
Re: is a catch can needed? why not just a breather filter? (Farnsrocket)
I still think you will need a vacuum source to draw vapors out when you are not boosting. Maybe I am wrong here.
pcv box>catch can>intake vacuum
ELIMINATING the pcv valve itself? that post was a little confusing with so many opinions (as usual
)
01-23-2003, 07:54 PM
#14
Join Date: Jul 2002
Location: East Bay, CA, USA
Posts: 2,374
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (keebler65)
I have my catch can set up as illustrated in the picture above. The line from the catch can goes right below my throttle body before the blower. This line never experiences boost, it is a constant vacuum source. Quite a few people have posted that boost will close the pcv valve. Am I right in assuming that they are referring to a turbo situation where the line to the intake would experience boost? Because I don't see how higher positive pressure on the crankcase side would cause the pcv valve to close.
01-23-2003, 07:57 PM
#15
Honda-Tech Member
Join Date: Jan 2002
Location: Colorado Springs, CO, USA
Posts: 1,822
Likes: 0
Received 1 Like
on
1 Post
Re: is a catch can needed? why not just a breather filter? (keebler65)
But, if you eliminate the PCV valve, then under boost, there will be positive pressure pushing the vapors into the box instead of removing them from the system...
01-23-2003, 08:13 PM
#16
Honda-Tech Member
Join Date: Aug 2001
Location: Bangkok, Thailand, Thailand
Posts: 4,096
Likes: 0
Received 1 Like
on
1 Post
Re: is a catch can needed? why not just a breather filter? (servion)
OK I'm really confused now.
Plus I heard that when running a boosted B18C with a B20B shortblock, the catchcan is useless. Can someone please explain?
Plus I heard that when running a boosted B18C with a B20B shortblock, the catchcan is useless. Can someone please explain?
01-23-2003, 08:19 PM
#17
Honda-Tech Member
Join Date: Aug 2002
Posts: 6,112
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (sharkcohen)
I have my catch can set up as illustrated in the picture above. The line from the catch can goes right below my throttle body before the blower. This line never experiences boost, it is a constant vacuum source. Quite a few people have posted that boost will close the pcv valve. Am I right in assuming that they are referring to a turbo situation where the line to the intake would experience boost? Because I don't see how higher positive pressure on the crankcase side would cause the pcv valve to close.
01-23-2003, 08:56 PM
#18
Honda-Tech Member
Join Date: Jul 2002
Location: Fortress of Wangatude, USA
Posts: 359
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (servion)
OK. After some thought, I came up with this. Let me know what you think. If someone else has already done this, please tell us how it works. I don't think there would be much, if any, oil make it to the turbo this way. Maybe I'm completely wrong. I don't know. I haven't tried this, so don't hold me responsible for anything. This is just an idea that I had for all the FI guys (and gals) out there. (Easy on the artwork comments. I'm not an artist, nor do I claim to be.
JB
[Modified by d16apwr, 12:01 AM 1/24/2003]
JB
[Modified by d16apwr, 12:01 AM 1/24/2003]
01-23-2003, 09:28 PM
#20
New User
Join Date: Aug 2001
Location: Golden/Denver, Co, USA
Posts: 1,025
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (Stu)
For those of you who read the link to that other thread...I was think about the exhaust vaccum source right before I saw the one Earl drew. That is a good idea. Then I was thinking about my buddy's car. (He is on here 2000ITR#700, I think) Anyway, he basically has a setup where the downpipe is a Y-pipe. Half of the exhaust goes out the exhaust system, and the other half just goes out the Y-pipe. You could get your constant vaccum source off of the part that dumps to the atmosphere.
Or, what about getting your vaccum source from you wastegate dumptube? How well do you think that would work?
Or, what about getting your vaccum source from you wastegate dumptube? How well do you think that would work?
01-23-2003, 09:35 PM
#21
New User
Join Date: Aug 2001
Location: Golden/Denver, Co, USA
Posts: 1,025
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (d16apwr)
JB, you could just run the line into the exhaust to get a constant vaccum system. Also, if you were worried about reversion, couldn't you jst use a one-way check valve in the line somewhere?
01-23-2003, 09:39 PM
#22
Join Date: Sep 2002
Location: You wish I was..., USA
Posts: 1,341
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (Stu)
For those of you who read the link to that other thread...I was think about the exhaust vaccum source right before I saw the one Earl drew. That is a good idea. Then I was thinking about my buddy's car. (He is on here 2000ITR#700, I think) Anyway, he basically has a setup where the downpipe is a Y-pipe. Half of the exhaust goes out the exhaust system, and the other half just goes out the Y-pipe. You could get your constant vaccum source off of the part that dumps to the atmosphere.
Or, what about getting your vaccum source from you wastegate dumptube? How well do you think that would work?
Or, what about getting your vaccum source from you wastegate dumptube? How well do you think that would work?
With the wastegate you only have a vacuum when the gate opens so it really wouldn't work right.
I think through the exhaust would be the best, but the one with the catch can collecting all the vapors and putting them into the turbo intake would be the easiest to do. Those two would be ideal... I think.
01-23-2003, 09:45 PM
#23
New User
Join Date: Aug 2001
Location: Golden/Denver, Co, USA
Posts: 1,025
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (tzsir)
For those of you who read the link to that other thread...I was think about the exhaust vaccum source right before I saw the one Earl drew. That is a good idea. Then I was thinking about my buddy's car. (He is on here 2000ITR#700, I think) Anyway, he basically has a setup where the downpipe is a Y-pipe. Half of the exhaust goes out the exhaust system, and the other half just goes out the Y-pipe. You could get your constant vaccum source off of the part that dumps to the atmosphere.
Or, what about getting your vaccum source from you wastegate dumptube? How well do you think that would work?
I would think dumping to the one going straight into the atmosphere wouldn't have enough of a vacuum, but I could be wrong there.
With the wastegate you only have a vacuum when the gate opens so it really wouldn't work right.
Or, what about getting your vaccum source from you wastegate dumptube? How well do you think that would work?
I would think dumping to the one going straight into the atmosphere wouldn't have enough of a vacuum, but I could be wrong there.
With the wastegate you only have a vacuum when the gate opens so it really wouldn't work right.
01-23-2003, 09:51 PM
#24
Join Date: Sep 2002
Location: You wish I was..., USA
Posts: 1,341
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (Stu)
Not in a FI application though. The air right before the turbo will be the fastest air in the entire system. Faster = more vacuum.
Also if you plug the vacuum source like the WG set-up you'll get oil going into the breather on the valve cover. Not really a good thing that have happening. The pressure in the crank case would also spike before it goes into the breather. That in itself can reduce the life of your rings. It's best to stay as close to the stock concepts as possible for reiability.
Also if you plug the vacuum source like the WG set-up you'll get oil going into the breather on the valve cover. Not really a good thing that have happening. The pressure in the crank case would also spike before it goes into the breather. That in itself can reduce the life of your rings. It's best to stay as close to the stock concepts as possible for reiability.
01-23-2003, 10:52 PM
#25
Honda-Tech Member
Join Date: Mar 2002
Location: Anaheim, CA, USA
Posts: 6,093
Likes: 0
Received 0 Likes
on
0 Posts
Re: is a catch can needed? why not just a breather filter? (tzsir)
If you run a pcv valve...which is 1 way going back into the intake manifold, it will be closed when boosting. The pressure in the intake manifold will fill the line and force the check valve closed. Now the exhuast gas is traped in the crankcase. The only place for it then to go is to that tiny little port on the valve cover. That is not very big to let all those gasses go out through.